69 



tha parts of which the ner^e-celLs are intercalatei. But, it 

 is certainly a fact worthy of njentiin, the fibrous constit- 

 aents of the layer do aot have their origin there, penetrating 

 it, rather, froin deeper levels. The dendrites of the Purkinje 

 neurones, and the processes from the neurogliar cells comprise 

 one great class of constituents. These take a course perpin- 

 dicalar to the surface and cause the vertical striation /»hich 

 is so luarked a feature of the region. Then, too, the neurones 

 of the granular layer send their axones outvjard into the rnolec- 

 ular layer for a T-shapei division, each thus giving origin to 

 a pair of fibres. These branches take a course across the 

 sagittal plane of the cereb9llu-n, parallel at once with the 

 limitans externa and the lateral surface of a fold. To the 

 presence of these fibres, cut across in such numbers in a 

 sagittal section of the cerebellun, the characteristically 

 punctate appearance of the molecular layer is chiefly due. 

 Finally, it should also be noted, there are numerous termina- 

 tions in the molecular layer of nerve-fibres which have entered 

 the cerebellum from some other region of the nervous system. 

 Such terminating fibres branch so as to distribute the endings 

 over a considerable superficial are^. 



It will thus be seen that the molecular layer is really 

 a tangle of nervous tissue, a series of paths where many asso- 

 ciations may be formed. This topic will be discussed more at 

 length in the fifth subsection. 



The neurones proper to the molecular layer are, as already 



